Roasting furnace



Apr. 3, 1923.

. 1,45030@ H. HOLTHOFF- ROASTING FURNACE &se t i a HENRY C. HOLTHOFF, OF MILVI'AUKEE, VJSCJNSN, ASSGNOR TO ALLIS-CHALMERS MANUFACTURING COMPANY, OF IiLIL JVAUKEE, VISCONSN, A CORPOBATION OF DELAWARE.

ROASTING FUENACE.

Application filed April 7, 1321. Serial No. 459306.

To all whom ?It may concrn:

Be it known that HENRY C. HoL'rHorr, a citizen ot the United States, residing at Milwaukee, in the county ot Milwaukee and State of Wisconsin, has invented a certain new and useful Improvement in Roasting Furnaces, ot which the following is a specification.

This invention relates to improvements in rabble arms which form part ot' the agitating or raking mechanism common to certain types of roasting furnaces where crushed ore is heated progressively in traveling through superposed hearths to release the sulphurous content and other chemical ele ments that pass oti in the form of gases whose presence, i' retained, would retard the processes which finally extracts the more valuable minerals.

It isthe exposure of the ore to the heat generated in these turnaces that expels the products to be eliminated. The necessary exposure to said heat is obtained by rakingg` the crushed ore over fioors, inwardly and outwardly in a radial direction with respect to a vertical rabble shaft, and in this wise turn the crushed charge over and over so that every possible amount of undesirable matter will be driven off before the final discharge point of the furnace is arrived at.

It is obvious, therefore, that a thorough stirring, raking or plowing of the charqe in transit will heighten the efiiciency ot the gas expelling operation and 'acilitate the ore reduction, while incdentally releasing greater quantities ot' sulphuric gas which is entrained and stored, thereby increasing the quantity of an element recovered, while 01: Chemical value, that holds a rofitable place in the list of by-products produced in modern mining Operations; besides re'ducing, to a minimum, the liability of atmospheric contamination which destroys vegetation and 'frequently raises objectionable proteste that restrict the development of inining operatons in certain localities.

An object of this invention is to present the ore products to rows of rabbles that furrow, as in plowing, having their ralzes or rabbles staggered to form overlapping sets ot share-like elements which keep the ore charges turning over while following a couse towards the discharge outlet, directed thereto by the fixed angular ptch of Inner and outer rabble rakes, respcctivcly forming, the first and last unit which comprises the quota of rabbles carried by a revolving arm.

inother feature is the mounting of raking elements or rabbles so as to leavewearing parts pivotally tree while acting as plow shares drawn through the crushed ore and able to right themselves after contact with obstructions that may momentarily deflect them; also, in providing a Construction that will allow the positioning of rabble units in staggered relationship to each other without requiring 'any departure from the form ot rahhle arms now largely employed in this field of endea'vor.

N ticeable in this improvement is a phase of Construction which provides a rabble comprised of separate members, one of which being designed to encounter the abuse resulting froni 'trictional contact with the ore charge This Contacting member is fashioned so as ,to offer the advantage of reg' lacing worn out parts at less cost than fornerly, while permitting the retention of other parts to be used indefinitely instead of discarding same as was the practice heretotore, this latter feature being of economical importance in fields of Operations dis-' tantly removed from Centers of supply.

The accompanying drawing` illustrates how these objects are obtained and discloses the applicability ot this improvement to rahble arms, ot acce-pted design, employed in this art, in which Fig. l is a plan view of a rabble arm equipped with this improvement; Fig. 2, a side elevation ot Fig g Fig. 3, a section on line H HI ot l; Fig. 4, a section on line lV-lV oi? Fig. 1 and Fig. 5 is a plan view ta plow share member detached.

Reierring more particularly to the drawina'. the 'following detailed description appnes similar characters of reference to like parts throughout the several views.

A hollow rabble shaft 2 supports a radially extending hollow arm 3, the latter proviced with the .ins 4 over which is slidably mounted, rabble shoes 5, 6, that are maintained in position upon the arm 3 by virtue oi the outer shoe 6 beingkeyed to the fins t by the dowels 7, and a limiting fin enlargement or shoulder 8 against which the inner sho-e 6 abuts. he shoes 6, in this manner, maintain a plurality oi the shoes 5 between them. Integral with the shoe 6 is a rabble blade 9, angularly disposed, to correspond to the direction inparted to the ore, the blades 9, disclosed in the drawing, apply to an outward direction of ore travel.

The shoes are provided, in one instance, with depcndingand integral brackets 10 that extend forwardly of their respective shoes whose fiared wings are spread to accommodate the brackets 10, 12 aforesaid. mnediately behind, and integrally with the forwardly inclined points 14 of the rabble shares 13, are fashioned the pivotal bosses 15 that are centrally bored in alinement with lower disposed lugs having openings 16, for the reception of fixed spindles 17, the latter loosely passing through the said bosses and lugs, but restrained against revolving in having` squared heads 18 that insures against their turning by virtue of rectangular openings 19 in which the heads 18 rest. This Construction leaves the rabble shares free to rock, as shown dotted in Fg. 1, about their respective spindles and also positions the said shares forward of their respective brackets, which arrangement protects the said braclrets from the wearing effects of the passing charge and furthermore offers a two part unit that permits of the ready removal or installation of rabble shares when replenishing of these parts become necessary.

During the operation of the furnaces, to

p which this invention applies, the rabble arms 3 revolve in the direction ndicated by the arrow in Fig. 1. The crushed ore,not shown in the drawing, is plowed or stirred by the shares 13, exposing the charge to the action of the heat present in the hearths through which the said charge is being swept. The communicating passages that connect the separated hearths, here referred to, and through which the ore charge progresses are arranged alternately; one opening being adjacent the outer radius line described by the revolving arm 3, serves as an outlet and inlet for adjoining hearths; the other opening is forned concentric about the central rabble shaft 2, similarly functioning. These features being well known in the art will require no further description where.

The direction in which the charge travels, outward or inward, is deternined by the angularity of the blades 7 of therabble shoes 6. The function of the intermediate shoes 5 with their shares. 13, is that of a thorough mixing or stirring of the crushed ore by furrowing said ore. The plow-like features of the shares 13 allows them to defiectand turn over the products to be roasted; also the pivoted provision which permits of the shares Swing-'ing to allow for the retarded passage of oversized luinps that form obstructions encountered by the points 14:, thereby` avoiding a pushing action that Would shove along the said lumps which in turn encounters otherlunps that serve to bring together a mass that would form an objectionable barrier which would prevent the ore from passing freely between the rabble shares. This objection is eliminated by the pivoting of the rabble shares 13 so as to allow large particles to be deflected to either side of the shares. The said shares being pivotally mounted adjacent their points 14; leaves their greater area behind their respective, pivots where the action of the charge, diverging at the points ll-,ten ds to right the shares after same have beendefiected-or rocked by the obstructions referred to above; thus, making the shares 13self adjustable for resuming and maintainingtheir normal positions.

It will be understood that it isnot desired to be limited to the exact details of Construction shown and described, for obvious modifications will occur to a person skilled in the art.

It is claimed and desired to secure by Letters Patent:-

1. In combination, a rabble support, and a rabble associated with and automatically adjustable relatively to said support.

2. In combination, a rabble support, and a rabble carried by and automatically horizontally adjustable relatively to said support. i

3. In combination, a rabble support, and a self-adjusting rabble carried by said support.

4. In combination, a rabble support, and a rabble loosely pivotally associated with said support.

5. In combination, a rabble support, and a rabble loosely pivotally assocated with said support by .means of a substantally vertical pivot.

6. In combinatioma rabble support, a V- shaped rabble carried by said support, and a pivot associated with said support and located within said rabble.

7. In combination, a *rabble support, a rabble carried by said support and compris- .ing two intersecting walls forming a wedge, and a substantially vertical pivot depending from said support and located rearwardly of said walls near theintersection thereof.

8. In combination, a rabble arm, a sloe carried by said arin, and arabble associated with and automatically adjustable relatively to said shoe.`

9. In combination, a rabble arm, a shoe detachably connected to said arm, and a selfadjusting rabble carried'by said-Shoe.

10. In combnaton, a rabble arm, a Shoe carried by said arm and having a depending pivot, and a rabble carried by and freely movable about said pivot.

ll. In combinaton, a Shoe having a dependng pivot, and a rabble earried for- Wardly of and freely movable about said pivot.

l2. In combinaton, a rabble arm, a pluralty of rabble shoes detachably associated With said arm, each of said shoes having a depending pivot, and a rabble carred by and located in front of each of said pvots.

13. In combnaton, a rabble arm, a plurality of rabble shoes detaehably connected to said arm, each of said shoes having a depending braeket and a substantally Vertical pivot carred by said bracket, and e Wedgeshaped 'abble carried by and located in front of each of said pivots.

14. In combnaton, a rabble arin, and a plu'ality of 'a bbles carried by said arm, said rabbles being arranged in two substantially horizontal rows located in different Vertical planes.

15. In combnation, a, rabble arm, and a plurality of rabbles carried by said arm, said rabbles being ar'anged in two horizontal rows located in parallel Vertical planes, and the rabbles of one row being staggered reletvely to those of the other row.

In testmony Whereof, the signature of the inventor is axed hereto.

HENRY C. I-IOLTHOFF. 

